As from 6th April 2003, subject to conditions, parents and others (such as guardians) who are responsible for looking after children aged under 6 (or under 18 if the child is disabled) have the legal right to ensure that requests they make for flexible working arrangements (such as part-time work or working from home - WFH) are taken seriously by their employers. The request must be to enable the employee to care for the child and an important condition is that the employee must have been employed in his job for at least 6 months to be eligible.
With effect from 6th April 2007 the right to request flexible working is extended to employees with responsibility for caring for (i) spouses/ partners (ii) adult relatives as defined and (iii) adults living at the same address as the employee (see the Flexible Working (Eligibility, Complaints and Remedies) (Amendment) Regulations 2006, SI 2006/3314 and notes at Acts of Parliament etc/Work and Families Act 2006 ).
In May 2008 the government indicated that the right to request flexible working would be extended to all those with parental responsibility for children aged under 17. This change was implemented with effect from 6th April 2009 by the Flexible Working (Eligibility, Complaints and Remedies) (Amendment) Regulations 2009, SI 2009/595.
The 2010 Coalition Government's programme includes a proposal to consult on extending the right to request flexible working to all employees (an announcement in Parliament on November says that this will be "in the New Year" - see Hansard HC col 596W on 29th November 2010). Plans to raise, as an interim measure, the child age limit from 17 to 18 with effect from 6th April 2011 were dropped in February 2011.
For further details of the "historical" background see Flexible Working/background .
See also notes at Maternity/maternity leave/return to work (part-time) and at Family friendly proposals generally